In a wireless communication system, e.g., a cellular system, power control is an important consideration in design and operation of the wireless system. Power levels throughout the system directly affect the levels of interference that users experience when trying to communicate over the wireless links. In a wireless communications system, many wireless terminals operate on batteries, which have a limited energy storage level, which when expended, requires a battery recharge or replacement. This limited energy storage level corresponds to a limited and specific wireless terminal power on time, at a specific operational power level. If the wireless terminal's, operational power level can be reduced, the wireless terminal's operational life can be extended. Therefore, it is highly desirable for wireless terminals to conserve power whenever possible so as extend and maximize their useful operational life between battery recharges or replacements. If a wireless terminal is transmitting on a power level that is excess of its requirements, it is both wasting valuable energy and creating an unnecessarily high signal level, which may interfere with other users in the same cell and/or sector or adjacent cell and/or sector. The other user that is experiencing the interference may have to expend additional power to overcome the interference or one of the users may have to be switched to another channel to overcome the interference.
Power control signaling has been used in wireless systems. However, the methods employed have not been highly efficient and there is significant room for improvement. Wireless terminals may be commanded to transmit at different power levels to accommodate different burst data rates or to achieve different levels of signal reliability. Wireless terminals are in many cases mobile devices, moving throughout a system and experiencing different power requirements at different locations due to, e.g., variations such as range from base station, obstructions in the communications path, etc. In addition, as a plurality of wireless terminals operate in the system, the levels of interference experienced between those wireless terminals may vary disrupting communications with the base station and may require transmission power adjustments of the wireless terminals to overcome the interference levels for efficient and sustained communications with the base station. The inefficiencies in present systems result in high levels of signaling required to convey precise and current power control information between the base station and the wireless terminals. As the level of signaling dedicated to power control between the wireless terminal and the base station increases, communications bandwidth that could have been dedicated to other purposes, e.g, the communication of user data, is lost to power control signaling. This generally results in system trade-off choices of better power control with the advantages of conservation of batteries, lower levels of interference, and a more robust channel or more available bandwidth for more users, higher data transmissions rates, etc. Based upon the above discussion, it is evident that there is a need for improved apparatus power control methods and apparatus that can be used for wireless terminal power control.